C / C++ / MFC

2-Mar-04 1:39

May be this will of some interest.

www.gamedev.net[^]

Another cast problem

Mazdak2-Mar-04 0:46

2-Mar-04 0:46

I want to convert a char * to unsigned char[](or fill that array with char * string) but I can't find it, I can do reverse of it but not this one.

Mazy

"A bank is a place that will lend you money if you can prove that you don't need it." - Bob Hope

Prakash Nadar2-Mar-04 0:51

2-Mar-04 0:51

It will be helpfull with little bit of code that you are trying to convert.

char *pszString;
pszString = new char[20];

now pszString can store upto 19 bytes of string.
you can either access it as
pszstring,
if you want to access each char then
*(pszString+index)
or
pszString[index]

hope i answered ur question properly.

Rickard Andersson²⁰2-Mar-04 1:22

Rickard Andersson²⁰

2-Mar-04 1:22

Mr.Prakash wrote:
now pszString can store upto 19 bytes of string.

WRONG!
You allocated 20, right? How can you say it can hold 19 bytes then?
You know, it is starting from 0, that means 0 is the first element.

Rickard Andersson
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UIN: 50302279
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Prakash Nadar2-Mar-04 1:28

2-Mar-04 1:28

i allocated 20 bytes, 19 bytes for some string and the 20th for \0

David Crow2-Mar-04 7:43

David Crow

2-Mar-04 7:43

But ASCII 0 is still a valid character, it just happens to be a special one. Allocating 20 bytes on the heap means you can store 20 bytes.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Prakash Nadar2-Mar-04 13:16

2-Mar-04 13:16

DavidCrow wrote:
Allocating 20 bytes on the heap means you can store 20 bytes.

yep but you cant store 20 'A's

David Crow3-Mar-04 2:23

David Crow

3-Mar-04 2:23

Of course not. I was simply saying that your "now pszString can store upto 19 bytes of string" comment was off by one.

"The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

Mazdak2-Mar-04 1:27

2-Mar-04 1:27

Thanks for reply, I have a problem now, see this code:

for(int i = 0 ; i < sizeof(mypointer);i++)
   buffer1[i] = *(val+i);

sizeof(mypointer) cause the loop only run 3 times and other chars do not copy to array , if I change it to a larger number like 200 it works ok but I don't know how to get size of it dynamiclly.

Mazy

"A bank is a place that will lend you money if you can prove that you don't need it." - Bob Hope

Rickard Andersson²⁰2-Mar-04 1:32

Rickard Andersson²⁰

2-Mar-04 1:32

Mazdak wrote:
sizeof(mypointer)

Change to:

strlen(mypointer)

When you do sizeof of a pointer it returns the size of the pointer, not the length of the string.

Rickard Andersson
Here is my card, contact me later!
UIN: 50302279
Sonork: 37318

Mazdak2-Mar-04 1:44

2-Mar-04 1:44

Thanks again Rickard. Smile | :)

Mazy

"A bank is a place that will lend you money if you can prove that you don't need it." - Bob Hope

Prakash Nadar2-Mar-04 1:34

2-Mar-04 1:34

change it to this way.

for(int i = 0 ; *(val+i)!=NULL;i++)   
    buffer1[i] = *(val+i);

since pointers are always 4 bytes sizeof(anypointer) will always return 4

Prakash Nadar2-Mar-04 1:36

2-Mar-04 1:36

Mazdak wrote:
but I don't know how to get size of it dynamiclly.

strlen will give you the size of the string pointed by the pointer.

Mazdak2-Mar-04 1:42

2-Mar-04 1:42

Thanks.

Mazy

"A bank is a place that will lend you money if you can prove that you don't need it." - Bob Hope

Rickard Andersson²⁰2-Mar-04 1:15

Rickard Andersson²⁰

2-Mar-04 1:15

If I understand you, you want to copy the data from a char* to a unsigned char[]?

char* p = "bla bla";
unsigned char uch[WHATEVER_SIZE];
strcpy(reinterpret_cast<char*>(uch), p);
cout << uch << endl;

Rickard Andersson
Here is my card, contact me later!
UIN: 50302279
Sonork: 37318

Mazdak2-Mar-04 1:30